package util;

import java.util.Random;

public class RandomString {
	private static final char[] symbols = new char[62];
	static {
		for (int idx = 0; idx < 10; ++idx)
			symbols[idx] = (char) ('0' + idx);
		for (int idx = 10; idx < 36; ++idx)
			symbols[idx] = (char) ('a' + idx - 10);
		for (int idx = 36; idx < 62; ++idx)
			symbols[idx] = (char) ('A' + idx - 36);
	}
	private final Random random = new Random();
	private final char[] buf;

	public RandomString(int length) {
		buf = new char[length];
	}

	public String nextString() {
		for (int idx = 0; idx < buf.length; ++idx)
			buf[idx] = symbols[random.nextInt(symbols.length)];
		return new String(buf);
	}

}